Control mechanism



June 30, 1936. R. s. AUSTIN 2,045,821

CONTROL MECHANISM Original Filed April 20, 1931 Sheets-Sheet l INVENTORY 7 5 7 .5. fi'VST/A ATTORNEY June 30, 1936. R, s AUSTIN 2,045,821

CONTROL MECHAN I SM Original Filed April 20, 1931 2 Sheets-Sheet 2 ATTORNEY Patented June 30, 1936 PATENT OFFICE CONTROL MECHANISM Reed 8. Austin, Minneapolis, Minn., assignor to Charles M. Stroud, Minneapolis, Minn.

Application April 20, 1931, Serial No. 531,384

Renewed June 12, 1935 '14 Claims.

This invention relates to a device adapted to control an apparatus through which current is supplied, and while the invention might be applicable to various sorts of apparatus, it particularly is designed for use in connection with an,

oil burnerf Oil burners are now extensively used in furnaces, and as commonly constructed, comprise an ignition device operated by an ignition circuit, and an electric motor which usually opcrates a pump supplying fuel, and a fan for supplying air to the burner. The ignition is usually operated and after a short interval, the motor is started to supply the combustible mixture. It is also a common practice to supply some means for stopping the operation of the circuit and motor, should the burner fail to ignite. This is usually done by a protectostat or other device placed adjacent the burner or in the stack, which is operated by heat and controls an electrical circuit which will operate apparatus to break the ignition and motor circuits. It is desirable to have a mechanism which will operate if the burner fails to ignite and stop the ignition and motor apparatus, and after a certain period, to again operate the ignition and motor device in a further attempt to start the burner.

It is an object of this invention, therefore, to provide a control mechanism for an electrical apparatus which will stop the operation-of the apparatus under certain conditions, and which will subsequently again supply current to the apparatus, but will again cease to supply current under certain conditions.

It is a further object of the invention to provide a mechanism through which current is supplied to the ignition and motor circuits of an oil burner, and which will be actuated by the protectostat or stack device of the burner to stop the supply of current to the ignition and motor circuit should the burner fail to ignite, but which will, after a certain period, again supply current to the ignition and motor circuits in a bar will separate said contacts and stop the supply of current to the ignition and motor circuits, but which will, after a further movement 01 the thermostatic bar due to the heating means, engage other contacts to again supply current to the ignition and motor circuits of the burner.

It is also an object of the invention to provide such a device as set forth in the preceding paragraph, together with a second thermostatic bar, heating means for the same controlled by the protectostat or stack device, which second thermostatic bar will move to separate said second pair of contacts and again out off the supply of current to the ignition and motor circuits should the burner fail to ignite.

These and other objects and advantages of the invention will be fully set forth in the following description made in connection with the accompanying drawings, in which like reference characters refer to similar parts throughout the sev- Fig. 4 is a. View in vertical section taken substantially on line 4-4 of Fig. 1; and

Fig. 5 is a wiring diagram of the device. Referring to the drawings, a mechanism is shown comprising a plate II] which preferably will be made of insulating material. Said plate may be mounted in a casing ll having a flange Ila almut its lower edge, which flange is provided with a plurality of apertured bosses Hb adapted to receive screws for attaching the casing to some support. Said casing also has a plurality of lugs Hc having tapped holes lld therein adapted to receive attaching screwsl2 for a plate l0 and also attaching screws M for a bottom plate I 5 closing the bottom of casing ll. Binding posts "hi1, l8, I9 and 20 are secured in plate II], as shown in Figs. 1 and 2. Binding post It is adapted to have attached thereto a conductor 83 leading to the motor circuit of an oil burner. Post I1 is adapted to have a conductor 80 attached thereto leading to the ignition circuit .of the burner; post I8 is adapted to have a conductor attached thereto leading from the stack device or'protectostat used with the burner; post I9 is adapted to have a ground conductor attached thereto and post 20.receives the live wire supplying current to the device.

The control means for the ignition and motor circuits is shown comprising a post 2| secured in plate M and carrying an adjustable contact member 22. Post 2i is secured to post it by a metal strip 2M disposed beneath plate H3. Another post22 is secured in plate l2 some distance from post 28 and carries an adjustable contact member 24. Post 23 is connected to post (it by a metal strip 23a disposed beneath plate fill. Contacts 22 and 253 preferably are substantially in axial alinement and comprise headed and threaded members, the members having slots in one end adapted to receive a screw driver or adtion, the same carrying a contact 28a adapted to engage contact 22. Strip 28 also curves away from bar 26 in a direction opposite to strip 27] and also extends substantially parallel to said bar at its terminal portion, and carries a contact 29 adapted to engage contact 26. Bar 26 is provided with heating means comprising a heating element 38 held thereon by a thin plate M, which heating element may be of any suitable form, such as thin sheets of mica wound with very fine high resistance wire. Bars 2t and 311 are inserted in the split top of post 25 and held therein by a small headed and nutted bolt 25a.

Heating element 26 has one terminal conductor 32 extending from one end of its winding to 'a post 33 and the other terminal of the heating element has a conductor 34 extending to a post 35. Post 33 is connected by a conductor 36 beneath plate flll'to the post 1153. Plate 26 has secured thereto a flexible resilient conductor in the form of a metal strip 371, the same being reversely bent and having thereon a contact 38 adapted to engage one end of an adjustable contact member 39 threaded into post lll secured in plate l9 and having a slot 49a in its end adapted to receive an adjusting tool such as a screw driver. Post id is secured in plate it and is connected by a conductor 26b disposed beneath plate l 0 to post 35.

The parts so far described constitute one form of regulator for the ignition and motor circuits of the burner and per se form no part of the present invention.

A post 4!] is also secured in plate W and the same is connected by a conductor 32 beneath plate I to a post 53 also secured in plate it. Another post M is secured in plate W a short distance from post 23 and said posts 33 and M are provided at their tops with spring contact ps 45 adapted to receive the ends of a fuse 56 which is provided to prevent too large a current being supplied. Post M is connected by a conductor all disposed below plate M] to the post 20 through which current is supplied. The post M has secured therein a thermostatic bar Q8, such as a bi-metallic lar, having secured at its other end a rather long cylindrical contact member 49. Bar 48 also has secured thereto a heating element 50 held on said bar by a plate 5i. Plates 48 and Si are inserted in the split top of post 4| and clamped by the small headed and nutted bolt 52. Heating element 50 may be simi- 56 secured in plate it and which is connected by a conductor 57 disposed beneath plate 96 to the binding post. 59. Contact member 39 engages at one end with a contact member 58 carried adjacent'the end of a flexible resilient conductor in the form of a sheet metal strip 59, said strip being inserted in the split top of post '62 and held therein by a headed and nutted bolt 69a, said post being secured in plate I0. Post Bil-is connected by conductor 6! disposed beneath plate E0 to the post 25. A post 62 is secured in plate. and is connected by conductor 63 disposed bcneath plate ill to post W. A conductor. clip or contact '66 is held in place by and in contact with post 62 and has a vertically extending side carrying a contact 65 engaging contact 52. Contact member 49 is engageable at its other end with a contact member 66 carried at one end of the thermostatic bar 671', which bar is disposed in the split top of post 68 and clamped therein by a small headed and nutted bolt 69. Post 68 is connected beneath plate W by a conductcr m to post 25. Bar Bil carries a heating element ll held thereon by a bar 22 also held in post 68 by screw 69. Heating element M has one terminal connected by conductor 13 to a contact M secured in and insulated from bar 6? and projecting at one side thereof, said contact being adapted to engage a contact l5 carried at the end of a resilient metal strip llfisecured to contact 5 3. The other end of the heating element M is connected by conductor M5 to a post 56. I

In Fig. 5 a wiring diagram for the device is shown. A thermostat 25a is provided, illustrated as in the form of a thermostatic bar mounted on a suitable support and having a bracket thereon in which is carried a mercury tube 775a. Said tube has a pair of electrodes at one end adapted to be connected by the mercury in the tube when the tube is tilted, and one of these electrodes is connected to a conductor ll through which current is supplied. The other electrode is connected by conductor 178 to a conductor 23 and conductor 29 extends to. and is connected to post 20 which is in turn connected to post 416 by a conductor M7. The fuse 66 extends between posts Q3 and M to limit the amount of current supplied and post 43 is connected by conductor 32 to-post M. Post M has connected thereto as already described, the bar 48 carrying a heating element 50, one end of which is connected to post 56 by conductor 55 and. the other end of which is connected by con- F ductor 53 to contact 52 carried by bar 48. Bar 68 also carries contact 49, one end of which engages contact 58 carried on the strip 59 secured in post 62. Post-60 is connected by conductor SE to a post 25. Post 25 as already described, carries bar 2% having thereon the heating element 30, the ends of which are connected to the posts 33 and 25 by conductors 32 'and 34 respectively, post 33 being connected to ground by conductor 36. Bar 26 carries the strips-2i and 28 having thereon the contacts 28a and 29 engaging respectively contacts 22 and 24 carried in posts 2i and 23 respectively. Post 23 is connected by conductor 23a to post i! and the latter is connected by' conductor to ignition device 88 of the burner,

comprising the transformer having spaced electrodes 8|a, one of which is connected to ground by conductor 82. In operation a series of sparks pass between the electrodes 8| a. Post 2| is connected by conductor 2 la to post l8 and the latter is connected by conductor 83 to the motor 84 supplying oil and air to the burner, one side of said motor being shown as connected to ground by conductor 85. Bar 28 also carries a strip contact 31 having thereon contact 38 engaging contact, 39 carried in post 48. Post 48 is connected by a conductor 48b to post 35. The conductor 88 also extends from conductor 18 to a switch 81 which will be opened upon heat being applied to the protectostat or stack device 88 used with the burner.

Switch 81 is connected by conductor 89 to the post l8 and the latter is connected by-conductor 83 to post 82 carrying the clip 84 having a contact 85 engaging contact 54. Member 88 will also close a switch 98 connected to post 4| by conductor'92. A conductor 9| connects the open contact 98a of switch 98 to post 88. The conductor strip 18 is shown having the contact which engages contact 14 on bar 81 secured in post 88. Bar 81 carries the heating element 1|, one end of which is connected to post 58 by conductor 18a and the latter is connected to ground by conductor 51. The other end of heating element 1| is connected to contact 14 by conductor 13. Bar 81 also carries the contact 88 engageable with contact 49. Conductor 18 is shown connecting post 88 and wire 8| orpost 25. V

The operation of the device is as follows: When the temperature in the room drops sufilciently, thermostat bar 15a will flex, tilting tube 18a and causing the mercury therein to connect the electrodes thereof. Current will then flow from conductor 11 through the electrodes and conductor 18 to conductor 19, thence to posts 28, 43 and 44 to post 4| through said post, bar 48 and contact 49 to contact 58 to strip 59 and post 88 and through conductor 8| to post 25. Current then flows through post and strips 28 and 28 through contacts 29 and 24 which are normally in contact to post 23 and then through conductor 23a, post l1 and conductor 88, to the ignition device 8| and to ground. The ignition is now operated. Current is supplied to heating element 38 through bar 28 and strip 31 to post 48 and then through conductor 48b to post 35 and through conductor 34 to said element. Current passes from said element through conductor 32, post 33 and conductor 38 to ground. Bar 28 flexes towardthe left shown in Figs. 1 and 5. As bar 28 flexes toward the left, contact 28a moves toward and eventually engages contact 22, thus closing the motor circuitthrough conductor 2|a, post l8 and conductors 83 and85, or through strip 2 I a and post l6 as shown in Fig. 2. The motor now starts and oil and air are supplied to the burner. After a short time, upon further flexing of the free end of bar 28 to the left contacts 24 and 29 separate and the ignition is cut off. The burner should now be ignited. If the burner ignites properly, protectostat or stack device 88 will open switch 81. However, should the burner not ignite, current will be supplied from conductor 18 through conductors 88 to switch 81, then through conductor 89 to post l8, conductor 83 and post 82 and strip 64, through contacts 85 and 54 which are normally engaged and conductor 53 to heating element 58. Heating element 58 will heat bar 48 and cause the same to flex to the right as seen in Figs. 1 and 5 and after it has moved slightly,

contacts 49 and 58 which are normally in engage ment will be separated. This will cut off the curv back to contact 58.

rent supplied through posts 4| and 88 to post 25 and both the ignition and motor circuits will be broken. The ignition and motor of the burner will then be stopped and bar 28 with strips 21 and 28 will resume normal position. However, bar 48 will continue to flex as current is still supplied to heating element 58 and after it flexes to a certain degree, contact 49 will be brought into engagement with contact 88 carried by bar 81 members 58 and 49 being now separated. When this occurs, current can again flow to post 25 through post 4|, bar 48, contacts 49 and 88, bar 81, post 88 and conductor 18. Current is again then supplied to the ignition circuit through strips 28 and 28 and contacts 24 and 29 as already described. Current is again supplied to heating element 38 and bar 28 flexes as already described and the motor circuit is again closed in a short time by engagement with contacts 22 and 28. The burner motor 84 is thus again started, ignition device 8| operated and another opportunity given for ignition. When bar 48 was flexed, strip 18 and contact 15 engaged contact 14 and heat was supplied to the heating element 1| on bar 81, current passing through conductor 13, the heating element 1|, conductor 18a and to ground through post 58 and conductor 51. It may be mentioned that strip 84 carrying the contact 85 is under considerable tension and moves over with bar 48 as the latter flexes, so that contacts and 54 remain engaged when contacts 14 and 15 engage. Bar 81 is thus heated and flexes toward the right as seen in Figs. 1 and 5. When bar 81 thus flexes, it separates contacts 49 and 88 and the circuit furnishing current to post 25 is thus broken and the ignition and motor circuits are broken and the burner is again stopped. If the burner ignites properly upon the second attempt, protectostat 88 would open switch 81 and thus the circuit furnishing the heating current to heating elements 58 and 1| would be broken and the burner would continue to operate. Should the bar 48 be excessively heated and flexed too far toward the right, contacts 54 and 85 would be broken and said bar would cool slightly and flex back suffitrouble will soon be discovered and the apparatus can be brought to normal position by manipulating the thermostat 15a and the mercury tube 18. If this is set at a point below the temperature of the room in which it is disposed, the circuit will be broken through conductor 88 and no current will be furnished to the heating devices 58 and 1| and the parts will thus assume their normal positions. The burner would then be investigated to see why the same did not ignite.

Shou d the burner ignite on the second attempt,

protectostat 88 will, as stated, open switch 81, thus breaking the heating circuits for heating elements 59 and H. At the same time, switch 98 will be closed and current will be supplied to post 88. This is to prevent the ignition and motor circuits being broken and the motor stopped, when the contact 49 moves away from contact 88 and When the burner cools,

switch 81 is closed and switch 98 opened.

From the above description it is seen that applic-ant has provided a simple and cflicient control mechanism for an oil burner or other "apparatus and one which not only acts to stop operation of the burner upon an ignition failure, but which will again repeat the starting operation by operating the ignition and motor of the burner and :ill again stop the operation thereof should the burner fail to ignite. The device is simple in structure and can be inexpensively made and marketed. The device has been amply demon strated in actual practice and found to be very successful and efficient.

It will, of course, be understood that various changes may be made in the form, details, arrangement and proportions of the parts, without departing from the scope of the applicants invention, which generally stated, consists in a device capable of carrying out the objects above set forth in the parts and combinations of parts disclosed and defined in the appended claims.

What is claimed is:-

1. A switching device' for controlling a.plurality of'electrical circuits, each'circuit having a controlling contact therein having in combination a thermostatic member, a heating means therefor, a contact carried by said thermostatic member, a second thermostatic member, a heating means for said latter member, a contact carried by said second thermostatic member, means for supplying heat to said first mentioned heating means including a resilient member having a contact thereon and a contact on said first thermostatic member engaged by said latter contact, said first thermostatic member being adapted to flex upon being heated and move said first mentioned contact to cut ofi the current to said controlling contacts and upon further flexing movement, to engage said first mentioned contact with the contact of said second thermostatic member and again supply current to said controlling contacts, and means for supplying heat to said second mentioned heating means.

2. The structure set forth in claim 1, said last mentioned means including a contact carried by said first thermostatic member and a contact carried by said second thermostatic member, which contacts are brought into engagement by movement of said first thermostatic member, said contact on said flexible member and the first thermostatic member remaining in engagement until said last mentioned pair of contacts are engaged.

3. A switching device for controlling the supply of current to a plurality of electrical circuits, which circuits have therein respectively fixed adjustable contacts having in combination, a pair of movable members having contacts thereon adapted respectively to engage said first mentioned contacts, a thermostatic member through which current is supplied to said movable members, a safety and repeating means for said regulator comprising a plurality of thermostatic members, a plurality of pairs of contacts controlled respectively by said thermostatic members through which current may be supplied to said first mentioned movable members, heating means for each of said thermostatic members, and means for supplying current to each of said heating means including a pair of contacts constructed and arranged to be separated if said thermostatic member is excessively heated and out 01f current to said heating means.

4. A switching device for controlling the supply of current to a plurality of electrical circuits having in combination means for supplying current to said circuits, a pair of thermostatically operated members, heating means for each of said members, means for supplying current to one of said heating means for moving one of said members aoeasci to render said first mentioned means inoperative after a time period and to subsequently render such means again operative after a certain period, and means for supplying current to said other heating element to cause said other thermostatically operated member to again render said first mentioned means inoperative after a certain second period, after a second time period.

5. The structure set forth in claim 4, said means for supplying current to said heating means for said last mentioned thermostatically operated member including acircuit closed by movement of said first mentioned thermostatically operated member.

6. A switching device for controlling the supply of current to a plurality of circuits, having in combination, a thermostatic member, a pair of contacts, one of which is carried by said thermostatic member through which current is supplied to said circuits, a second pair of contacts controlled by said thermostatic member and through which current is supplied to said circuits, means for heating said thermostatic member after a time period to 'fiex said thermostatic member and separate said second pair of contacts and cut off current from said circuits, another pair of contacts controlled by said thermostatic memher and subsequently closed by further flexing of said thermostatic member to again supply cur- 30 rent to said circuits.

7. A switching device for controlling a plurality of circuits having in combination, a current supply circuit, a temperature responsive means having contacts normally closing one of said plurality of circuits and having a contact adapted to close a second of said circuits when said means is heated, a heating circuit for said means, a second temperature responsive means arranged to act subsequently to said first mentioned temperature responsive means having a contact adapted to break said current supply circuit when said second temperature responsive means is heated, a heating circuit for said second temperature responsive means, a third temperature responsive means arranged to act subsequently to said second temperature responsive means and having a contact adapted to break said current supply circuit a second time when said third temperature responsive means is heated and a heating circuit for said third temperature responsive means closed after said second period of time.

8. The structure set forth in claim 7, said last mentioned heating circuit being closed by a contact moved by said second temperature responsive means when heated.

9. The structure set forth in claim 7 and means responsive to heat for breaking either the heating circuit for said second temperature responsive means or the circuit for said third temperature responsive means whereby said current supply circuit will not be broken and said second of said plurality of circuits will remain closed.

10. A switching device for controlling the supply of current to a plurality of circuits having in combination, a pair of contacts through which current is supplied to said circuits, a thermostatic member controlling one of said pair of contacts and adapted to be flexed to separate said contacts, an electrical heating means for said member, a circuit through which current is supplied to said heating means including a pair of contacts, a resilient member on which one of said last mentioned contacts is carried normally under tension to move with the other of said pair 75 of contacts for a certain distance when said thermostatic member is flexed, said thermostatic member being constructed and arranged to flex sufficiently to separate said last mentioned pair of contacts whereby said last mentioned circuit will be broken and current cut oil from said heating means.

11. A switching device for controlling the supply of current to a plurality of circuits having in combination, a thermostatic member, a pair of contacts controlled by said member through which current is supplied to said circuits, a heating means for said thermostatic member operated after a time period for flexing said thermostatic member and separating said contacts to cut off the supply of said current to said circuits at said contacts and a second pair of contacts closed by the further movement of said thermostatic member to supply current to said circuits.

12. The structure set forth in claim 11, a second thermostatic member, one of said second pair of contacts being carried by said second thermostatic member, an' electrical heating means for said second thermostatic member and means for supplying current to said last mentioned heating means to move said last mentioned thermostatic member and separate said second pair of contacts to again cut off current from said circuits at said second pair of contacts.

13. A switching device for controlling the sup- 5 ply of current .to a plurality of circuits having in combination, means through which current is supplied to said circuits including a pair of contacts, a thermostatic member controlling one of said contacts to separate the same when heated, electrical means for heating said thermostatic member to cause it subsequently to separate said pair of contacts, a second pair of contacts, one of which is carried by said thermostatic member, which second pair is engaged after a further heating and flexing of said thermostatic member and a circuit closed by said last mentioned pair of contacts.

14. The structure set forth in claim 13, a second thermostatic member, means for heating said second thermostatic member to flex the same and separate said last mentioned pair of contacts after a certain period, whereby current is again cut oil from said circuits.

' REED S. AUSTIN. 

